1. Field of the Invention
The present invention relates to modular building structures, and more particularly to moveable partition systems making use of easily installed and removed modular panels to separate interior office space.
2. Description of the Prior Art
The cost of new construction has made custom-designed office space a thing of the past for most businesses. It would therefore be a goal for newer office buildings to put their available space to the maximum, beneficial use with a floor plan that could easily be altered for each change in tenant. Unfortunately, no such universal floor plan exists and remodeling costs for moving walls and electrical connections can significantly effect the rental marketability of a property.
To reduce the costs inherent in framing new interior walls and for redesigning electrical systems, the concept of temporary, modular room dividers has been developed. These temporary structures can broadly be classified into two different groups, the sound/sight panels, and the semi-permanent interior wall structures. The sound/sight panels function as little more than modernized versions of oriental privacy screens. Examples of such structures may be found in U.S. Pat. No. 3,762,116 to Anderson, et al.; U.S. Pat. No. 3,871,153 to Birum, Jr.; U.S. Pat. No. 3,788,378 to Sobel; U.S. Pat. No. 4,269,005 to Timmons; and U.S. Pat. No. 4,296,579 to Proud. Most of these panel structures simply rest upon pedestals and the like. However the more complex, such as that disclosed by Halsey, et al, U.S. Pat. No. 3,282,006 make use of springs to bias the panels between the ceiling and the floor.
As is the case for oriental screens, these panel structures are designed to provide little more than partial barriers to outside distracting sights and sounds. Even if building and fire codes permitted, these structures are not designed to provide an electrical distribution network. When the moveable partition network is being used to, in effect, re-wire the office space, a more substantial structure is required. Such electrical dividers fall in the class of semi-permanent interior walls. An example of such a construction is provided for in U.S. Pat. No. 3,195,698 to Codrea.
Regardless of the system used, all enclosed office space must be provided with light, ventilation, and access to communication/electricity. The utilities of light and ventilation are exceedingly difficult to re-route once the permanent building structure is completed. Even in the newer buildings that make use of false ceilings to house the lights and ventilation system, changing the original design will typically require a major remodeling effort, particularly with respect to ventilation. Both heat/cooling and air, must be provided through new conduits, along with new or additional outlets into the room. Frequently, an additional supply source and a supply grid is needed for the electricity or the air to respond to the greater demand for that utility. The difficulties inherent in redesigning the light and ventilation systems are one of the principal reasons that most moveable partitions and modular walls do not extend continuously from the floor to the ceiling. Most such systems stop well short of the ceiling, permitting the use of the existing light and ventilation supplies for the revised modular office space.
A standard requirement for most businesses is an adequate supply of office electrical and communication outlets. Where temporary and modular dividers are used, it becomes necessary to provide a new electrical conduit system to meet the requirements of the revised floor plan. The conduit system must be installed in a manner that satisfies local building codes, and even if otherwise permissible, esthetics alone require the new wiring system to be substantially out of view. In addition, although the conduit network must be out-of-sight and protected from the wear and tear of office life, access to the system must remain readily available for ease of maintenance and repair. Moreover, since flexibility is one of the beneficial characteristics offered by modular systems, the associated electrical system must be easily modifiable to match the subsequent changes made to the original floor plan, and these modifications must be able to be performed in a straight-forward and an inexpensive manner.
For those modular systems that provide an electrical system, the electrical pathways are provided through one of two methods. Some modular panels are true "plug-in" designs, with the individual panels pre-wired and connected to one another through electrical connectors formed as part of the panel. Such systems are shown in U.S. Pat. No. 4,270,020 to Kenworthy, et al.; U.S. Pat. No. 4,231,630 to Propst, et al.; and U.S. Pat. No. 4,239,932 to Textoris, et al.
The alternative to the "plug-in" modular systems, one that provides a greater degree of flexibility, makes use of raceways formed within the modular partitions to carry the necessary electrical and communications wires. After formation of the partitions, the wiring is placed in the most appropriate raceways to create the power grid required by the plan. An example of such a raceway system is shown in Codrea, U.S. Pat. No. 3,195,698, previously cited herein. The raceway passages permit the wiring to be placed where needed for a particular application, whereas the "plug-in" system avoids the necessity for wiring the partition subsequent to assembly. A combination of both systems is taught by Haworth, et al., in U.S. Pat. No. 4,060,294.
An additional characteristic that is important for a successful modular design is the adaptability of the design to the existing building structure. None of the moveable partitions are designed or intended to be placed into load-bearing situations, and thus the modular design must readily adapt to all of the peculiarities of the preexisting building. One of the major problems that is encountered by pre-fabricated structures is the lack of orthogonality or squareness in even the most lavishly of constructed buildings. Floors and ceilings are frequently not parallel with one-another, and in fact, may be misaligned by as much as two or three inches over the space of only several feet.
One of the more traditional methods for leveling a partition system is to provide a threaded support foot that may be turned to raise or lower the support column. Such a system is disclosed in U.S. Pat. No. 3,194,361 to Thurman. Leveling screws are also provided in Radek, U.S. Pat. No. 4,185,422, with the operation of these leveling screws apparently much like the trial-and-error method used to level many of the larger household appliances.
In addition to the problems caused by uneven floors, the multi-piece modular unit must ultimately function as a unitary structure. This requires that each of the separate pieces be connected, and although the early systems used conventional screws and bolts, one of the selling points of modular units is their ease of fabrication. The conventional forms of attachment such as screws and bolts require openings that are difficult to machine and, more importantly, increase the installation time since they must be tightened down to a certain torque level. The modular systems very quickly evolved their own attachment methods--most designed to require the minimal use of hand tools. The early systems such as Anderson, et al., U.S. Pat. No. 3,762,116, and Bleeker, U.S. Pat. No. 3,809,142, utilize peculiarly shaped connecting structures, some of them spring-loaded, to form the intermodular connections. Eventually most systems came to use some type of metal clipping arrangement, whether the Ushaped connectors of, for example, Halsey, et al., U.S. Pat. No. 3,282,006, or the more complex connecting plates of Gartung, U.S. Pat. No. 4,185,430. All of these metal plate connectors rely on the clamping force of the clip to keep the separate units together, and rely on friction to keep the metal plate connectors in place. Added security can be obtained by utilizing both metal connecting plates and bolts, such as in Timmons, U.S. Pat. No. 4,269,005.
Regardless of the type of connector used, the goal for all modular systems is to provide a method for connecting the individual units that permits the greatest amount of design freedom in selecting a floor plan. In tension with this characteristic of freedom is the requirement that the design enables the rapid installation of the modules while obtaining a structurally sound partition with rapidly installed modular units.
In addition to the physical hardware that keeps the system standing, a modular partition structure must also provide an aesthetically pleasing appearance, one that also gives the impression that the partition is structurally sound. A number of different finishing materials have been used on the modular panels from wood/wood-veneer to particle board, plastic, and fabric.
There is a tendency for the rectangular office space created by the modular units to have very "live" acoustical characteristics, as the sound rebounds from wall to wall. Fabric wall coverings tend to dampen or diminish this effect, but present a more difficult cleaning problem than do the wood and wood-like surfaces. In addition to cleaning problems, fabric also has a tendency to fade and otherwise simply wear out over time. Many systems that use fabric covers enable the simplified removal of the covers, either by removing the entire panel, such as in Sobel, U.S. Pat. No. 3,788,378, or by removing the fabric covering, such as is shown in Decker, U.S. Pat. No. 4,112,643 and Birum, Jr., U.S. Pat. No. 3,871,153. In at least one system, Proud, U.S. Pat. No. 4,296,579, a multi-element panel is used, with all of the elements easily removed upon removal of the outer fabric covering. This ability to achieve the ultimate in tear-down characteristics, however, disadvantageously results in a panel construction having a lessened degree of structural integrity than would be the case where the fabric covering overlays an integral acoustic structure.
The market for open office systems is highly competitive with new designs and modular systems being introduced with great regularity. This rapid level of innovation is in part due to the constantly changing nature of the office environment, but the principal reason for innovation is the improvements made at many levels to the design features of modular systems.
Since the modular units are essentially all prefabricated, there is a constant effort to further reduce set-up time by reducing the need for conventional fastening systems. These efforts are complicated by the simultaneous tendency to make the unit designs more complex, and to provide a greater number of ways in which the units can be placed together.
The electrical system and the manner in which it is routed through the modular units presents a further continuing problem. Some office systems only require the most rudimentary of wiring schemes, while others require electricity and communication lines in a complex, interrelated network. Since the same modular units must be used if the partition system is going to be a viable commercial product, the modulars must provide great flexibility in the electrical design area.
A still further design problem is created where the "semi-permanent" modular systems become more or less permanent. Office requirements change over time, and the in-place units must provide the ability to respond to these changes. Access to the electrical system must be readily available--without the necessity for tearing apart large sections or, where avoidable, removing fixtures that have become attached to the modular walls. Moreover, nothing can be more out-of-date than last year's fabric styles, decorating ideas, etc. In addition, no one likes to work in areas that have become tacky or seedy due to faded or damaged walls, and the modular units must provide for both of these contingencies by having easily changed wall surfaces.